U.S. Pat. Nos. 4,717,949, 4,829,365, 5,036,385, 5,040,878, and 5,457,574 disclose autostereoscopic display devices with an array of thin, vertical, parallel, equidistant, light emitting lines behind a flat, transmissive, electronically controlled display panel, such as a liquid crystal display (LCD), to generate for an observer a perception of three dimensional images. These patents describe various means for generating an array of thin lightlines as the means for creating stereoscopic images, however they all utilize light sources which are not coplanar with their lightguides. The backlighters described in these prior patents vary in cost and complexity, but they all share the disadvantage of having backlighters which are too thick for some of today's applications, such as lap top computers, and which consume more power than is desirable, especially for battery operated devices.
Planar or edge-lit backlighters are known in the prior art such as shown in U.S. Pat. Nos. 5,126,882, 5,339,179, and 5,359,691. These types of backlighters are useful in lap top computers and the like, however none of these patents disclose how to incorporate autostereoscopic technology into planar backlighters. Therefore, there is a need for a simple, low cost autostereoscopic system capable of providing clear, bright, high resolution images with a relatively thin planar back lighting system as is necessary for use in today's thin portable computer systems, televisions, and other electronic display devices. There is also a need to provide a planar back lighting system with the capability of switching back and forth from 3-D to 2-D images. There is further the need to provide an autostereoscopic system of smaller size, which uses less lamps and less power, takes up less space, and is less expensive to produce than existing systems.